EP 0474315 A2 19920311 - Microwave discharge light source apparatus.
Title (en)
Microwave discharge light source apparatus.
Title (de)
Apparat mit Mikrowellen-Entladungs-Lichtquelle.
Title (fr)
Appareil àvec source lumineuse à décharge à micro ondes.
Publication
Application
Priority
- EP 88906879 A 19880727
- JP 18825687 A 19870728
Abstract (en)
A power supply circuit for a magnetron adapted to supply microwave energy to an electrodeless discharge bulb is disclosed the circuit comprises a rectifier coupled across a commercial AC voltage source, a filter for smoothing the output of the rectifier, an inverter for converting the DC voltage supplied from the filter into a high frequency AC voltage, a step-up transformer for stepping up the high frequency AC voltage outputted from the inverter, and a rectifier which rectifies the high voltage AC output of the transformer into a unidirectional voltage which is supplied to the magnetron. The inverter switching is controlled by a pulse width modulation control circuit to maintain the magnetron output power at a predetermined level. According to one aspect, an inductance is provided in the circuit which supresses high frequency components in the currents flowing through the windings of the transformer; according to another aspect, the inverter switching frequency (expressed in kHz) is set at a value not less than 1500/D, wherein D represents the diameter of the electrodeless bulb expressed in millimeters; according to still another aspect, the peak to the mean value ratio of the magnetron current is limited under 3.75 inclusive. <IMAGE>
IPC 1-7
IPC 8 full level
H01J 65/04 (2006.01); H05B 41/24 (2006.01); H05B 41/282 (2006.01); H05B 41/392 (2006.01)
CPC (source: EP KR US)
H01J 65/04 (2013.01 - KR); H01J 65/044 (2013.01 - EP US); H05B 41/24 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT NL
DOCDB simple family (publication)
WO 8901234 A1 19890209; CA 1304773 C 19920707; DE 3853169 D1 19950330; DE 3853169 T2 19951026; DE 3853835 D1 19950622; DE 3853835 T2 19960215; DE 3874721 D1 19921022; DE 3874721 T2 19930422; EP 0326619 A1 19890809; EP 0326619 B1 19920916; EP 0474315 A2 19920311; EP 0474315 A3 19920701; EP 0474315 B1 19950517; EP 0474316 A2 19920311; EP 0474316 A3 19920701; EP 0474316 B1 19950222; JP H07111918 B2 19951129; JP S6433896 A 19890203; KR 890702238 A 19891223; KR 920001875 B1 19920306; US 4988922 A 19910129; US 5053682 A 19911001; US 5115168 A 19920519
DOCDB simple family (application)
JP 8800753 W 19880727; CA 573179 A 19880727; DE 3853169 T 19880727; DE 3853835 T 19880727; DE 3874721 T 19880727; EP 88906879 A 19880727; EP 91202577 A 19880727; EP 91202578 A 19880727; JP 18825687 A 19870728; KR 890700491 A 19890320; US 32978689 A 19890317; US 61624490 A 19901120; US 61625790 A 19901120